Heating apparatus



y 1945' L. MUELLER Y 2,376,173

HEATING APPARATUS Filed Sept. 9, 1943 2 Sheets-Sheet 1 I (56 INVENTOR.

E wr z A M 1 HTrOA /Ey 2 Sheets-Sheet 2 M. L. MUELLER HEATING APPARATUS Filed Sept. 9, 1943 May 15, 1945.

M LMMV1\\|J r 225457521372 5 my M 1' All/I. e 1U! .7 17,1 m w v u m M gig 1 A 0 .lll Z a g M 4 w M M w, 4 M IIIIIITIIIifi I i I I II a m f4 2 a 6 h n 4 2 4M 4 Z Lk I -|||v IMF 2w 3 L. Al 0 1 e, u ul l x n| n n E Patented May 15, 1945 HEATING APPARATUS Moritz L. Mueller, Seattle, Wash, asslgnor by mesne assignments, to Moritz L. Mueller and John H; Mueller, Seattle, Wash, as joint tenants Application September 9, 1943, Serial No. 501,613

6 Claims. 401.237-2) This invention relates to heating and air circulating systems and has particular reference to 'a low cost heating system for supplying heated air to a space in a building to be occupied by and Y although not limited, for use in heating one-story homes where no basement is employed;

To provide a simple and inexpensive heatin 4 system which is adapted to promote the circulation of heated air throughout the house and which is also adapted for withdrawing heated .air from the house during the time when it is not .desired to supply heat to the space in the house;

To provide an inexpensive heatingsystem for a small house in which the fuel burning apparatus thereof may also be utilized as a cook stove.

and -in which system provision is made for preventing the overheating of the kitchen and for distributing heat from the kitchen inwhich the cook stove is arranged to other portions of the house.

Other objects and advantages of the invention will be apparent from a consideration of the following specification taken in conjunction with the accompanying drawings, of which there are two sheets and wherein:

Fig. 1 is a vertical cross section through a part of a house illustrating one form of heatin system embodying the invention and the method of circulating the air to be heated through the heating system and the house;

Fig. 2 is an enlarged vertical sectional view of the heat exchange and air circulating part of the system;

Fig. 3 is an enlarged fragmentary view of the air circulating apparatus and the relief vent of the system;

Fig. 4 is a plan view of the interior arrange ment of the house having the heating system ared therein; I

Fi 5 is a plan view to the attic space of the house illustrating the air circulating system of the heating'system;

Fig. 6 is a fragmentary view similar to Fig. 2 and illustrating a modified form of the invention; and

- F g. 7 is a view illustrating the wiring diagram for the blower motor.

In Figs. 1, 4, and 5, there is illustrated a house or dwelling having a plurality of rooms 20, 22, and 24 with an attic space 26 between the roof 28 of the dwelling and the ceiling 30 over such rooms. The attic preferably is vented in any' suitable manner, such for example as by a louvered open ing 25 to atmosphere. A heating system embodying the invention is provided for heating the space in the rooms and comprises ingeneral a chimney 32 forming part of aheat generating and recovering apparatus which is provided with a plurality of outlets 34 through which heated air is discharged to the space in the various rooms.

As illustrated in Fig. '4, the room 24 may consist of a combination living r in, dining room and kitchen, such as now e loyed in many of the defense homes being ere ted, and have heat generating apparatus comprising a stove 36 arranged therein. As illustrated in Fig. 2, the stove 36 includes a combustion chamber 12 which may be adapted for burning hard fuel such as coal, under natural draft conditions and be provided with a flat top 38 which forms a cooking top, as well as an oven. A water heating coil 'of a hot water system may be thermally associated with combustion chamber 12. In Fig. '4 the direction of flow of the heated air discharged through the outlets 34 is indicated by arrows. and from these it will be seen that one of the outlets 34 may be arranged to discharge air directly into the room 24 and another of the outlets may be arranged to discharge air toward the entrance to the rooms 22 and 20, which may be bedrooms, and another of the outlets may be connected by a short section of pipe 40 so asto discharge heated air into a small room 421 which might be used as a bathroom. The particular room arrangement disclosed is used merely as one example.

Return air outlets 44 may be arranged in the with the rooms 20, 22 and 24 in such a way as to induce a circulation of heated air across the rooms from the heated air outlets 34, and as indicated in Fig. 1, these returnair outlets communicate with vertically extending ducts 46 formed in the walls of the dwelling, the ducts 46 at their upper ends communicating with lateral ducts 48 which deliver the return air to a pipe 50 which communicates with the intake side of the air blower 52. The upper end of pipe 50 opens into a laterally extending pipe 54, one end of which communicates with the intake side of the blower 52 while the other end of the pipe 54 is provided with a damper 56. g

A plate 56 closes the lower part of the right hand end (Fig. 3) ofpipe 54, while the damper 58 is pivoted to the plate 58 and is adapted to close the opening 60 formed in the end of the pipe 64 above the plate 66. In Fig. 6 the damper 66 is shown in its open position, the position it is adapted normally to assume when the blower" is not operating. A weight 62 may be provided for insuring movement of the damper 66 to. the position in which it is illustrated in Fig. 3. The

damper 66 is adapted'to move in a counterclockwise direction so as to close the opening 66, and this action is brought about by operation of the blower 62, the damper 66 being so arranged that flow oi air into the opening 66 will move the damper" to position to=close the opening 66 and trated, and which form a path for conducting air to be heated in intimate countercurrent heat exchange relationship with the flue gases which flow upwardly through the path 66 provided internally of the chimney 62.

The chimney 62 extends upwardly from its base to and above the roof 26 of the building, and is provided with an atmospheric vent I6 through which the products ot'combustion are discharged into the atmosphere. Heated products of combustion are generated in the combustion chamber 12 by the burning of fuel'therein, and such heated products of combustion are supplied through 'a pipe I4 to the lower end of the flue path or duct 66, the height of the chimney 62 being sufiicient to induce enough draft in the combustion chamber I2 so as to support combustion therein under natural draft, the combustion chamber 12 being supplied. with air through suitable air intake openings (not shown).

The blower 62 is adapted to be driven by a motor I6, the circuit of which is illustrated in Fig. 7. The motor circuit I6 includes a hand-operated switch 66 and thermostatic switch 62. When both the hand switch 66 and thermostatic switch 62 are closed the motor I6 is adapted to drive the blower 62, which in turn will efl'ect the circulation' of air from the space in the rooms 26, 22 and 24 upwardly through the wall ducts 46, then laterally through the ceiling duct 46, thence through pipes 66 and 64, blower 62, elbow 66, heat exchanger member 66, andwarm air outlets 64.

11' at such time heated products of combustion are being generated in the combustion chamber I2, the passage of air through'the heat exchanger member 66 will absorb heat from the flue gases in the flue gas passageway 66. The thermostatic switch 62 has the thermal element 64 arranged in the flue passageway 66 just above the upper end of the heat exchanger member 66, and preferably is set so that when the flue gas temperature at this point reaches a predetermined degree, say for example 225 FL, the switch 62 will close and cause operation of the motor .16 and blower 62. When the temperature of the flue gases at this point falls below a predetermined degree, say for example a temperature of 125 F., the thermal element will open the switch 62, thereby discontinuing the operation of the blower.

As previously described, the damper 66 will open the relief vent 66 upon the stopping of the blower and will close the opening 66 upon starting of the blower. In this way the air path provided by seem the heatexchangermember 66 isopen atitstop, as well as at its bottom, whenever the blower I2 is stopped. In this way, if the circuit of the motor should be open for any reason whenever heated products of combustion are being generated in the combustion chamber 12, heat will be dissipated from the heat exchanger member 66 by thermosiphonic flow of air therethrough. For example, in the summertime when it is desired to employ the stove 66 for cooking or other purposes without having heat supplied to the house, the

- switch 66 may be opened, thereby cutting out the thermostatic switch 62 and preventing the operation of the blower 62.

As the stove 66 is arranged in the kitchen 24 and exposed to the air therein, it will not only give off radiant heat, but will also dissipate heat to the air in the kitchen. Under some circumstances the kitchen may become too warm, and to relieve this situation a bleed or damper-controlled air intake 66 may be provided for admitting air from the upper part of the kitchen to the duct 46 which is on the intake side of the blower 62. A damper 66 pivoted at 66 is adapted to close the opening 66, the damper 66 normally being held open by gravity. A cord 62 passing over a pulley 64 may be connected to the free end of the damper for moving the same to its closed position, and the cord may be anchored to a bracket 66 for holding the damper in closed position. If the inlet 66 is Open during the heating season, warm air trom the kitchen will be drawn through the inlet 66 into the air circulating system, and after passing through the heat exchanger member 66 and the warm air outlets 64, may be distributed to the various parts of the house. In this way a better distribution of heat throughout the house may be obtained.

An air conduit I66 connected at one end I62 thereof to the lower end of the heat exchanger member 66 is adapted to conduct air from the heat exchanger member 66 to the outside of the dwelling. As illustrated in'Fig. 2, the conduit I62 may extend through the floor of the dwelling and when the damper I64 thereof is open, as illustrated in Fig. 2, the air which has passed through the heat exchanger member 66 may be discharged externally of the house. During the time that heat is supplied to the house the damper I64 should be closed so that the air may be forced through the outlets 64. However, when the damper I64 is open, the outlets 64 may be closed by dampers I66 so that-all of the air which passes through the heat exchanger member 66 will be discharged externally of the-house. In this way, when the stove 66 is operated during the summertime, heated air may be withdrawn from the kitchen through the air inlet 66 to the duct 46, as well as from the various rooms through the outlets 44, and if desired a shunt may be provided around thermostatic switch 62 so that the blower 52 may be operated without regard to the temperature of the flue gases adjacent the thermostatic element 64.

In the modification illustrated in Fig. 6, the construction and operation of the system is the same except in the following particulars. The products of combustion are supplied through pipe I26 to the interior of heat exchanger member I22. The upper end of the heat exchanger member I22 is centered by a plate or baffle I24 which forms a seal between the outside of the heat exchanger member I22 and the inside wall of the chimney I26. Air from the blower 52 is supplied through the discharge 64 thereof to the air path which is formed between the heat exchanger member,

I22 and the walls of the chimney I 26. Above the plate I24 and heat 'exchangermember I22 the walls of the chimney"! formthe flue gas passageway which leads to an atmospheric vent. Below the heat exchanger meinber I22 the air path I28 may be provided with outlets, as'shown 'in Fig. 2, for discharging heated air into the" space in the rooms, as-well: as with a connectionlike the conduit 100 for optionally delivering the Y heated air externally of the space insidethe house.

As the attic pm?" is vented to atmosphere and as the relief vent 60 opens into the attic, the

air passageway of the heating apparatus will be vented externally of the space to which heat is normally supplied, when the damper I6 is open. In addition, as thewarm air outlets uare'open said air blower as aforesaid without interfering with the generation of heated products of combustion in said combustion chamber when it is desired to use said stove for cooking purposes for the purpose of cooking without supplying heated air to said space, and a by-pass between except when the damper I is open, the space:

which is normally supplied with. heat is vented through the air path of the heating apparatus and the vent 60 through theattic to atmosphere when the blower 52 is not operating, although this, as well as the venting of the air path of the heating system. may becontrolled by' the dampers I05.

While the invention has been described with some detail, it is tobe understood that the description is for the purpose of illustration only and is not definitive of the limits of the inventive idea. The right is. reserved to make such changes above the roof of the building and has an atmospheric discharge, a stove in one of said rooms having a I combustion chamber provided with means for burning fuel so as to generate heated products of combustion and a cooking surface,

a heat exchanger member extending longitudi-.

nally of and for a substantial ortion of the length of said chimney, said heat exchan er member and chimney providing a path for the upward now of the products of combustion from said combustion chamber to said atmospheric discharge and a separate path for flow of air in intimate countercurrent heat exchange relation ship withthe combustion products, a flue connection between said combustion chamber and the lower end of said combustion products path.

means including a return air duct and a blower operable to supply from said space to the upper end of said air path, air to be heated and under a pressure greater than the pressure of the products of combustion in said combustion products path, the inlet end of said return air duct communicating with one of said rooms other than that one in which said stove is arranged, the lower end of said air path having an outlet for discharging heated air into said space. an electric motor for operating said air blower, an electric circuit for said motor including a thermoplastic switch having a thermal element responsive to thetemperature of the combustion products at' the upper end of said heat exchanger member and adapted to close the circuit so that said air blower will be normally operated when heated products of combustion are being generated at a substantial rate, a manually operated switch in said circuit for preventing the operation of the upper end of said room in which said stove is located andsaid return air duct for withdrawing heated air from said room.

2. In a heating system for a building for-human occupancy having space to'be heated and an'attic thereabove, said space providing'a plurality of rooms, a chimney which forms part of the'building and which extends upright to and above the roof of the building and has an atmospheric discharge, a 'stove in one of said rooms having a combustion chamber provided with means for burning fuel so as to generate heated products of combustion and a cooking" surface, a heat exchanger member extending longitudinally of and for a substantial portion of the length of said chimney; said heat exchanger member andchimney providing a path for the upward flow of the products of combustion from said combustion chamber to saidatmospheric discharge and a separate path for flow of air in intimate countercurrent heat exchange relationship with the combustion products, a flue connection between said combustion chamber and the lower end of said combustion products path, means including a return air duct and a-blower operable to supply from said space to the upper end of said air path, air to be heated and under a pressure greater than the pressure of the products of combustion in said combustion p oducts path, the inlet end of said return air duct communicating with one of said rooms other than that one in which said stove is arranged, the low-- er end of said air path having an outlet for discharging heated air into said space, an electric motor for operating said air blower, an electric circuit for said motor including a thermostatic switch having a thermal element responsive to the temperature of the combustion products at the upper end of said heat exchanger member and adapted to'close the circuit so that said air blower will be normally operated when heated products of combustion are being generated at a substantial rate, a manually operated switch in said circuit for preventing the operation of said air blower as aforesaid without interfering with the generation of heated products of combustion in said combustion chamber when it is desired to use said stove for cooking purposes without operating said air blower, said air path having a relief vent at the upper end thereof communicating with the attic and adapted for venting said air path so as todissipate from said heat exchanger member the heat absorbed thereby when said fuel burning means are operated for the purpose of cooking without supplying heated air to said space, a by-pass between the upper end of said room in which said stove is located and said return air duct for withdrawing heated air from said room, and means connected to the ower end of said air path for discharging the heated air therefrom externally of said space.

3. In a. heating system for a building for human occupancy having space to be heated comprising tion from said combustion chamber to said atmospheric discharge and a separate path for flow of air in intimate countercurrent heat exchange relationship with the combustion products, a flue connection between said combustion chamber and the lower end of said combustion products path. means including a return air duct an a blower operable to supply from said space to the upper end of said air path, air to be heated and under a pressure greater than the pressure of the products of combustion in said combustion products path, the inlet end of said return air duct communicating with one of said rooms other than that one in which said stove is arranged, the lower end of said air path having an outlet for discharging heated air into said space and another outlet for discharging air externally of said space, damper means for selectively controlling the flow of air through said outlets, an electric motor for operating said air blower, an electric circuit for said motor including a thermostatic switch having a thermal element responsive to the temperature of the combustion products at the upper end of said heat exchanger member and adapted to close the circuit so that the air blower will be normally operated when heated products of combustion are being generated at a substantial rate, a manually operated switch in said circuit for preventing the operareturn air duct having a d change relationship with the combustion products, a flue connection between said combustion chamber and the lower end of said combustion products path, means including a return air duct and a blower operable to supply from said space totheWWendofsaidairpatha-irtobeheated and under a pressure greater than the pressure of the products of combustion in said combustion products path, the inlet end of said return air duct communicating with said space near the floor thereof and remote from said stove, the lower end of said air pathhaving an outlet for discharging heated air into said space near the floor thereof, an electric motor for operating said air blower, an electric circuit for said motor including a thermostatic switch having a thermal element responsive to the temperature of the combustion products and adapted to close the circuit so that the air blower will be normally operated when heated products of combustion are being generated at a substantial rate, a switch adapted to open said circuit for preventing the operation of said air blower as aforesaid without interfering with the generation of heated products of combustion in said combustion chamber when it is desired to use said stove for cooking purposes without operating said air blower, said air path having a relief vent at the upper end thereof adapted to open externally of said space for venting said air path so as to dissipate from said heat exchanger member the heat absorbed thereby when said fuel burning means are operated for the pifi'pose' of cooking without supplying heated a to said space, said per controlled inlet above said stove for withdrawing air from said space during operation of said blower.

tion of said air blower as aforesaid without in- I terfering with the generation of heated products of combustion in said combustion chamber when it is desired to use said stove for cooking purposes without operating said air blower, said air path having a relief vent at the upper end thereof adapted to open externally of said space for venting said air path so as to dissipate from said heat exchanger member the heat absorbed thereby when said fuel burning means are operated for the purpose of cooking without supplying heated air to said space, a damper adapted to close said vent during operation of said blower, and a by-pass between the upper end of said room in which said stoveis located and said return air duct for withdrawing heated air from said room, and a damper for controlling said by-pass. I I

4. In a heating system for a building for human occupancy having space to be heated, a chimney which forms part of the building and which extends upright to and above the roof of the building and has an atmospheric discharge, a stove in said space having a combustion chamber provided with means for burning fuel so as to generate heated products of combustion and a cooking surface, a heat exchanger member extending longitudinally 'of and for a substantial portion of the length of said chimney, said heat exchanger member and chimney providing a path for the upward flow of the products of combustion from said combustion chamber to said atmospheric discharge and a separate path for flow of air in intimate countercurrent heat ex- 5; In a heating system for a building for human occupancy having space to be heated, a chimney which forms part of the building and which extends upright to and above the roof of the building and has an atmospheric discharge-a combustion chamber provided with means for burning fuel so as to generate heated products of combustion and a cooking surface, a heat exchanger member extending longitudinally of and for a substantial portion of the length of said chimney, said heat exchanger member and chimney providing a path for the upward flow of the products of combustion from said combustion chamber to said atmospheric discharge and a separate path for flow of air in intimate countercurrent heat exchange relationship with the combustion products, means including a return air duct and a blower operable to supply from said space to the upper end of said air path, air to be heated and under a pressure greater than the pressure of the products of combustion in said combustion products path, the inlet end of said return air duct communicating with said space remote from said combustion chamber, the lowerend of said air path having an outlet for discharging heated air into said'space, an electric motor for operating said air blower, an electric circuit for said motor including a thermostatic switch having a thermal element responsive to the temperature of the combustion products and adapted to close the circuit so that the air blower will be normally operated when heated products of combustion are being generated at a substantial rate, a switch adapted to open said circuit for preventing the operation of said air blower as aforesaid without interfering with the generation of heated products of combustion in said combustion chamber when it is desired to generate heated products of combustion for cooking purposes without operating said air blower, said air path having a relief vent at the upper end thereof adapted to open externally of said space for venting said air path so as to dissipate from said heat exchanger member the heat absorbed thereby when said fuel burning means are operated for the purpose of cooking without supplying heated air to said space, and a by-pass between the upper end of said space adjacent said chimney and said return air duct for withdrawing heated air from said space during operation of said blower.

8. In a heating system for a building for human occupancy having space to be heated, a chimney which forms part of the building and which extends upright to and above the roof of the building and has an atmospheric discharge, a combustion chamber provided with means for burning fuel so as to generate heated products of combustion and a cooking surface, a heat exchanger member extending longitudinally of and for a substantial portion of the length of said chimney, said heat exchanger member. and chimney providing a path for the upward flow of the prodnets of combustion from said combustion chamber to said atmospheric discharge and a separate path for flow of air in intimate countercurrent heat exchange relationship with the combustion products, means including a return air duct and a blower operable to supply from said space to the upper end of said air path, air to be heated and under a pressure greater than the pressure of the products of combustion in said combustion pro-.

ducts path, the inlet end of said return air duct communicating with said space remote from said combustion chamber, the lower end of said air path having an outlet for discharging heated air into said space, an electric motor for operating said air blower, an electric circuit for said motor including a thermostatic switch having thermal element responsive to the temperature of the combustion products and adapted to close the circuit so that the air blower will be normally operated when heated products of combustion are being generated at a substantial rate, a switch adapted toopen said circuit for preventing the operation of said air blower as aforesaid without interfering with the generation of heated products of combustion in said combustion chamberwhen it is desired to generate heated products of combustion for cooking purposes without operating said air blower, said air path having a relief vent at the upper end thereof adapted to open externally of said space for venting saidair path so as to dissipate from said heat exchanger membeer the heat absorbed thereby when said fuel burning means are operated for the purpose of cooking without supplying heated air to said space, a by-pass between the upper end of said space adjacent said chimney and said return air duct for withdrawing heated air from said space during operation of said blower, and means connected to the lower end of said air path for'discharging the heated air therefrom externally of said space.

MORITZ L. MUELLER. 

